Padres win 6-4, sweep Giants

Updated 11:05 pm, Sunday, April 28, 2013

A subdued line of Giants watches the final half-inning of the Padres' three-game sweep in San Diego.

A subdued line of Giants watches the final half-inning of the Padres' three-game sweep in San Diego.

Photo: Denis Poroy, Getty Images

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Jose Mijares is helpless to prevent Alexi Amarista from scoring on a passed ball.

Jose Mijares is helpless to prevent Alexi Amarista from scoring on a passed ball.

Photo: Denis Poroy, Getty Images

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San Diego Padres' Chase Headley strokes one of his three extra base hits against the San Francisco Giants in a baseball game in San Diego, Sunday, April 28, 2013. (AP photo/Lenny Ignelzi)

San Diego Padres' Chase Headley strokes one of his three extra base hits against the San Francisco Giants in a baseball game in San Diego, Sunday, April 28, 2013. (AP photo/Lenny Ignelzi)

Photo: Lenny Ignelzi, Associated Press

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SAN DIEGO, CA - APRIL 28: Brandon Crawford #35 of the San Francisco Giants makes diving stop on a single hit by Everth Cabrera #2 of the San Diego Padres during the fourth inning of a baseball game at Petco Park on April 28, 2013 in San Diego, California. Crawford couldn't make the throw to first in time. (Photo by Denis Poroy/Getty Images)

SAN DIEGO, CA - APRIL 28: Brandon Crawford #35 of the San Francisco Giants makes diving stop on a single hit by Everth Cabrera #2 of the San Diego Padres during the fourth inning of a baseball game at Petco

SAN DIEGO, CA - APRIL 28: Nick Hundley #4 of the San Diego Padres is congratulated by Alexi Amarista #5 (R) as Jason Marquis #21 (L) and Buster Posey #28 of the San Francisco Giants look on after Hundley hit a two-run homer during the second inning of a baseball game at Petco Park on April 28, 2013 in San Diego, California. (Photo by Denis Poroy/Getty Images)

SAN DIEGO, CA - APRIL 28: Nick Hundley #4 of the San Diego Padres is congratulated by Alexi Amarista #5 (R) as Jason Marquis #21 (L) and Buster Posey #28 of the San Francisco Giants look on after Hundley hit a

San Diego Padres' Alexi Amarista is congratulated in the dugout after his two-run home run against the San Francisco Giants in the fourth inning of a baseball game in San Diego, Sunday, April 28, 2013. (AP Photo/Lenny Ignelzi)

San Diego Padres' Alexi Amarista is congratulated in the dugout after his two-run home run against the San Francisco Giants in the fourth inning of a baseball game in San Diego, Sunday, April 28, 2013. (AP

SAN DIEGO, CA - APRIL 28: Chase Headley #7 of the San Diego Padres hits a solo home run as Buster Posey #28 of the San Francisco Giants looks on during the first inning of a baseball game at Petco Park on April 28, 2013 in San Diego, California. (Photo by Denis Poroy/Getty Images)

SAN DIEGO, CA - APRIL 28: Chase Headley #7 of the San Diego Padres hits a solo home run as Buster Posey #28 of the San Francisco Giants looks on during the first inning of a baseball game at Petco Park on

SAN DIEGO -- Yielding home runs in bunches and making mental and physical mistakes in bunches are the marks of a mediocre team, not a defending world champion. In the past five games, the Giants have been the epitome of mediocrity.

"It's always frustrating when you lose," Buster Posey said. "I don't sense any tension or anybody overly frustrated. It's more of a drive and willingness to want to work and get back on track."

It'll have to wait another day. On Sunday, the Giants extended their season-high losing streak to five games, falling 6-4 to the Padres. It's their longest skid since a five-gamer, July 25-30, a streak that began against the Padres with a game that Jason Marquis won and Huston Street saved.

Just like Sunday's. Marquis out-pitched Ryan Vogelsong, who surrendered three home runs - a theme for Giants starters - and Street overcame Pablo Sandoval's fourth single and retired Posey to complete the Padres' first sweep of the Giants since 2010.

"When you're in a streak like this," manager Bruce Bochy said, "it's a number of things, whether it's pitching, hitting with runners in scoring position or defensively. That's what's happening with us."

In the five losses, the Giants hit .237, including .179 (7-for-39) with runners in scoring position, and committed six errors and several others not seen in the box score. The rotation's ERA was 3.72 only because five of six runs permitted by Barry Zito on Saturday were unearned as a result of Andres Torres' error.

No National League West rotation gives up homers like the Giants'. That's 21 for the fivesome (three more than runner-up San Diego), a third courtesy of Vogelsong, who was victimized Sunday by Chase Headley, Nick Hundley and Alexi Amarista.

Vogelsong has a 6.23 ERA with only one quality start (at least six innings, no more than three earned runs) in five assignments. In one stretch last year, he had 16 straight quality starts.

"I'm trying some stuff that has worked in the past, mechanically," he said. "I've been watching a lot of video from the last two years and trying to find something I can repeat. That seems to be the problem, not repeating very well."

The streak started with two losses to the Diamondbacks, thanks in part to Didi Gregorius taking advantage of late-game mental lapses by Giants outfielders, turning singles into doubles when Torres on Tuesday and Angel Pagan on Wednesday were slow to return the ball to the infield.

On Sunday, they trailed 6-2 before Posey hit a two-run homer in the eighth. Later in the inning, with two runners in scoring position, Torres hit a sharp liner to right. If it fell, the game would have been tied, and Torres would have somewhat redeemed himself for a sloppy stretch.

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